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2 years ago

Examine the system of equations -3x+y=4, -9x+5y=-1 what is the solution

2 answers:

5 0

Answer: x=-7/2 y=29/2

Steps:

Use the elimination method

Multiply -3x+y=4 by 5 to make the coefficient next to the y in both equations the same

5(-3x+y=4)

-15x+5y=20

Then, subtract to eliminate the y

-15x+5y=20
- -9x+5y=-1

= -6x=21
Divide both sides by -6 to isolate x

= x= -7/2

Next substitute -7/2 into x in one of the equations

-3(-7/2)+y=4

-21/2+y=4

Add 21/2 from both sides to isolate y

y=29/2

Evgesh-ka [11]2 years ago

3 0

Answer:

sorry i know im late but here

Step-by-step explanation:

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3 years ago

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Step-by-step explanation:

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3 years ago

Simplify the expression fraction with numerator of the square root of negative one and denominator of the quantity three plus ei

Ainat [17]

The right answer for the question that is being asked and shown above is that: "fraction with numerator negative 3 minus i and denominator 10." This is the simplified expression fraction with numerator of the square root of negative one and denominator of the quantity three plus eight times i minus the quantity two plus five times i.

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3 years ago

Read 2 more answers

If w = 12 units, x = 7 units, and y = 8 units, what is the surface area of the figure? Figure is composed of a right square pyra

bearhunter [10]

Answer:

720 sq units.

Step-by-step explanation:

Length and width of square prism, w = 12 units

Height of square prism, x = 7 units

Height of square pyramid, y = 8 units

Please have a look at the attached image.

Here 2 Surfaces will not be exposed which are base of the square pyramid and the top of the square prism i.e. 2 square surfaces will not be exposed.

Here, surface area of the composite figure will be:

Surface Area of Composite Figure = Lateral surface area of Square Pyramid + Surface Area of 5 surfaces of the square prism

For finding the lateral surface area of pyramid, we need to find the slant height of the pyramid.

Let slant height be $l$ units.

Using pythagoras theorem, we can find out the value of $l$ .

As per theorem:

$Hypotenuse^{2} = Base^{2} + Height^{2}\\$

$\Rightarrow l^{2} = (\dfrac{w}{2})^{2} + y^{2}\\\Rightarrow l^{2} = (\dfrac{12}{2})^{2} + 8^{2}\\\Rightarrow l^{2} = {6}^{2} + 8^{2}\\\Rightarrow l^{2} = 36+64 = 100\\\Rightarrow l = 10\ units$

Lateral surface area of square prism = 4 $\times$ Area of triangular surface

$\Rightarrow 4 \times \dfrac{1}{2}\times Base \times Slant\ Height\\\Rightarrow 4 \times \dfrac{1}{2} \times 10 \times 12\\\Rightarrow 240\ sq\ units$

Surface Area of 5 surfaces of the square prism =

$4 \times x \times w + w^2\\\Rightarrow 4 \times 12 \times 7 + 12^2\\\Rightarrow 336 +144\\\Rightarrow 480\ sq\ units$

So, total surface area of composite figure:

240 + 480 = 720 sq units.

7 0

3 years ago

Which of the following shows the best communicative property of addition ?

kumpel [21]

Answer:

In the given options, 4+5 = 5+4 shows the best commutative property.

Step-by-step explanation:

One of the properties that can be applied on numbers is commutative property. Commutative property states that the order of the numbers on which any operation is being performed, can be swapped and the answer won't change.

Commutative property can be applied on addition, subtraction and multiplication.

Commutative property of Addition:

Commutative property of addition states that changing the order of adding two numbers does not change the result i.e. a+b = b+a

In the given options, 4+5 = 5+4 shows the best commutative property.

3 0

3 years ago